1. Field of the Invention
The present invention relates to a heat pipe type heat exchanger for use in cooling, for example, semiconductor devices and the like.
2. Description of the Related Art
Heat pipe type heat exchangers are widely used to cool control devices that utilize a semiconductor device such as a power transistor or vehicle-mounted transistor, or thyristor.
As shown in FIG. 14, a conventional heat pipe type heat exchanger 20 is made up of a heat receiver block 21 that receives heat from an exothermic body, a plurality of heat pipes 13 having their base portions embedded in the heat receiver block 21 at a predetermined spacing, and an intermediate partition plate 18, fins 24 and a guide 17 that are assembled in sequence to the exposed portions of the heat pipes 13 from the base portions toward the top. The fins 24 dissipate heat from the heat pipes 13, and the intermediate partition plate 18 serves to divide the casing containing a semiconductor device (not shown) such as a thyristor and the like and the outside, while at the same time serving, along with the guide 17, to fasten the heat pipes 13 to one another. The heat receiver block 21 and the fins 24 are formed from a material with good thermal conductivity such as copper, aluminum or the like.
Such a heat pipe type heat exchanger is disclosed for example in Japanese Patent Application Unexamined Publication No. Hei 8-210789 (FIG. 4) and has features such as light weight, compactness, low maintenance and the like.
In recent years, as semiconductor devices have developed and come into wide use, the necessity has arisen of cooling semiconductor devices with larger heating values. Heat exchangers are generally used based on required capacities, i.e., heat sinks for a small capacity, heat pipes for an intermediate capacity, and thermosyphon type heat exchangers for a large capacity.
Shown in FIG. 15 is an example of a thermosyphon type heat exchanger. FIG. 15 is a partial exploded perspective view of a thermosyphon type heat exchanger 100, with components shown exploded. The thermosyphon type heat exchanger 100 roughly has a shape of two rectangular parallelepipeds placed one on the other and is comprised of a substantially rectangular parallelepiped condenser section 27, a substantially rectangular parallelepiped tank section 30 disposed below the condenser section 27, and a substantially rectangular parallelepiped front apron section 40 extending forwardly in the back-and-forth direction indicated by a double-headed arrow A.
The condenser section 27 is constituted by a partition plate 31, a combination of fins 41 and a header 50, a partition plate 31, a frame body 26 and a partition plate 31 laminated in this order in the back-and-forth direction indicated by the double-headed arrow A and joined together, with an end plate 37 joined to the front end. The condenser section 27 thus includes many rectangular spaces 26a defined by the frame body 26 and the two partition plates 31, 31 that hold the frame body 26 therebetween as well as many fins 41. To increase the heat dissipation action, the fins 41 are held between the two partition walls 31, 31. Furthermore, at the top end, there are formed a plurality of paths that allow flow therethrough of working fluid in gaseous phase, the plurality of paths being defined by a plurality of vapor paths 55 provided in the header 50, a plurality of vapor paths 35 provided in each partition plate 31, and the plurality of rectangular spaces 26a. 
The tank section 30 has therein the partition plate 31, a tank segment 25, the partition plate 31, the frame body 26 and the partition plate 31 joined together in this order in the back-and-forth direction such that working fluid paths 38 provided in the tank segment 25 align with corresponding liquid paths 34 provided in each partition plate 31, with an end plate 32 joined at the front end. The tank section 30 is thus formed with a plurality of liquid receivers, which partially open upwardly to receive working fluid in the liquid phase. An exothermic body (not shown) is connected to the underside of the tank section 30.
The front apron section 40 is made up of an end segment 28 and two corner segments 23, 23 and is primarily used to attach the thermosyphon type heat exchanger 100.
By the construction as mentioned above, a larger heat exchange area has been secured to enhance the cooling performance (see for example Japanese Patent Application Unexamined Publication No. 2002-13467 (FIG. 1)).
The large capacity thermosyphon type heat exchanger is excellent in performance, but is complicated in structure as indicated in FIG. 15 and thus is costly. To secure the same performance as obtained by the thermosyphon type heat exchanger with the conventional heat pipe type heat exchanger, which is simpler in structure than the thermosyphon type heat exchanger, many heat pipes would be required, eventually resulting in an increase in cost due to enlargement of the heat exchanger size, production difficulties and the like.